BEGIN;
BEGIN
EXPLAIN (ANALYZE, BUFFERS)
select
	c_count,
	count(*) as custdist
from
	(
		select
			c_custkey,
			count(o_orderkey)
		from
			customer left outer join orders on
				c_custkey = o_custkey
				and o_comment not like '%unusual%packages%'
		group by
			c_custkey
	) as c_orders (c_custkey, c_count)
group by
	c_count
order by
	custdist desc,
	c_count desc;
                                                                    QUERY PLAN                                                                     
---------------------------------------------------------------------------------------------------------------------------------------------------
 Sort  (cost=926739.41..926739.91 rows=200 width=8) (actual time=70067.812..70067.816 rows=46 loops=1)
   Sort Key: (count(*)), (count(orders.o_orderkey))
   Sort Method: quicksort  Memory: 27kB
   Buffers: shared hit=253756 read=37579 written=36
   ->  HashAggregate  (cost=926729.76..926731.76 rows=200 width=8) (actual time=70067.706..70067.722 rows=46 loops=1)
         Buffers: shared hit=253753 read=37579 written=36
         ->  HashAggregate  (cost=889229.76..904229.76 rows=1500000 width=8) (actual time=68830.960..69712.449 rows=1500000 loops=1)
               Buffers: shared hit=253753 read=37579 written=36
               ->  Hash Right Join  (cost=69028.00..814312.57 rows=14983439 width=8) (actual time=2420.862..50742.759 rows=15352708 loops=1)
                     Hash Cond: (orders.o_custkey = customer.c_custkey)
                     Buffers: shared hit=253753 read=37579 written=36
                     ->  Seq Scan on orders  (cost=0.00..445615.79 rows=14983439 width=8) (actual time=0.058..13659.263 rows=14852687 loops=1)
                           Filter: ((o_comment)::text !~~ '%unusual%packages%'::text)
                           Rows Removed by Filter: 162313
                           Buffers: shared hit=238087 read=17967 written=5
                     ->  Hash  (cost=50278.00..50278.00 rows=1500000 width=4) (actual time=2418.970..2418.970 rows=1500000 loops=1)
                           Buckets: 262144  Batches: 1  Memory Usage: 52735kB
                           Buffers: shared hit=15666 read=19612 written=31
                           ->  Seq Scan on customer  (cost=0.00..50278.00 rows=1500000 width=4) (actual time=0.010..1685.070 rows=1500000 loops=1)
                                 Buffers: shared hit=15666 read=19612 written=31
 Total runtime: 70100.053 ms
(21 rows)

COMMIT;
COMMIT